Preparation, characterization and photocatalytic activity of Si-doped and rare earth-doped TiO2 from mesoporous precursors

Si-doped and rare earth-doped TiO2 with large specific surface area were prepared by the hydrothermal method and sol-gel route, respectively, using C18H37NH2 as template. The samples were characterized by XRD, FT-IR, low-temperature N2 adsorption-desorption measurement, XPS and solid state UV-vis diffuse reflectance spectroscopy. The pore size for Si-doped TiO2 exhibits both mesoporous and microporous distribution, and that for rare earth-doped TiO2 exhibits a sharp and narrow distribution in microporous range. The photocatalytic activities were investigated with the degradation of phenol as probe reaction. Compared with pure TiO2, the conversion of phenol and selectivity to CO2 increases when adding rare earth elements, and the substitution of Si for Ti in an appropriate range also increases the conversion of phenol.